In order to be able to construct devices in industrial electronics more compactly, a plurality of printed circuit boards, which are equipped with components in two dimensions, are arranged on top of one another in a plurality of planes, and so the components that are present on all of the printed circuit boards collectively form one electronic circuit. Such circuits often contain plug-in boards, which can be inserted into connector devices on the printed circuit boards using an edge connector and can be electrically contacted by both printed circuit boards in this manner. Assemblies are often put together on plug-in boards when the intention is for them to be added to the circuit subsequently by the user or to be replaced during operation. Plug-in boards therefore contain in particular expansion modules for retrofitting additional functionalities or capacities, memory modules or wearing parts, which will probably be replaced during the service life of the device.
Edge connectors and the associated connector devices, which collectively form a “card edge” connector, are available in many sizes, structural shapes and having many numbers of contacts, each of which are standardized. If one plug-in board is to be in contact simultaneously with two printed circuit boards arranged on top of one another, a height difference between the planes, in which these two printed circuit boards extend, has to be bridged. Using the existing standardized connector devices, this can currently only be achieved by the part of the plug-in board having the edge connector, which is to engage in the connector device on the lower printed circuit board, projecting by the amount of the difference in height beyond the edge connector, which is to engage in the connector device on the higher printed circuit board. The plug-in board therefore needs a stepped edge if its edge connector is to engage in connector devices on both printed circuit boards simultaneously.
In industrial electronics it is often necessary to encapsulate plug-in boards in module housings to protect them from mechanical damage. In so doing, this presents problems if a plug-in board has a stepped edge.